When poor rural Southern whites use rural Southern dialect conservatives love itI guess I've never noticed that. The other stuff you mention, I agree with.
I read some neo-confederate boasting about how the "hillbilly" dialect of Appalachia represents the English of the Elizabethan period and the literary zenith of the language. I don't doubt it, either.
"Black" English doesn't come from Africa but from the British Isles (it conserves certain archaic British dialects). As one who grew up reading Uncle Remus and B. A. Botkin Southern folklore anthologies I must admit that (while I believe knowledge of Standard English should be taught to all) I have never considered the various venerable American dialects to be "leftwing" or in need of eradication.
Personally, I'm a big fan of Gullah.
Have to think on that one a little.
Ok. I'm done.
The Appalaichian dialect is probably Elizabethan remnants but that's like Cockney as representative of modern English. It is, more or less. The appalaichian sounds come from the uneducated portion of Elizabethan English and was/is not the zenith of anything.
Yeah? How many of your trusted physicians, lawyers, CPAs, financial advisors, therapists (if you have one), professors, military leaders, political leaders speak Gullah? Let me guess...none. But it probably is cute in an anthropological way to cruise through the sea islands and get the locals to say something.